Touch screens for electronic devices are mainly divided into resistive touch screens and capacitive touch screens. With the increasing size of the screen used in the electronic device, the capacitive touch screen is more and more widely used. The electronic apparatus of the capacitive touch screen (hereinafter referred to as touch screen apparatus) includes a receiving unit for receiving a signal, a sending unit for sending a signal, a mutual capacitance connected between the receiving unit and the sending unit and a data processing and analyzing module. The mutual capacitance forms a part of the touch screen. The data processing and analyzing module can detect the mutual capacitance by analyzing the signal received by the receiving unit and determine whether the touch screen is touched.
However, the detection of the mutual capacitance by the touch screen apparatus is susceptible to noise, i.e. the signal received by the receiving unit includes both the noise and the signal sent by the sending unit, and it is difficult to distinguish the noise from the sent signal, so it is difficult to eliminate the influence of the noise on the sent signal by filtering, and the detection of the mutual capacitance is directly affected.